1. Field
The present disclosure relates to an electric apparatus, and more particularly, to an electric apparatus including a rotor, a stator, and a shaft.
2. Description of the Related Art
An electric apparatus includes a rotor, a stator, and a shaft. Such an electric apparatus, for example, a generator includes a magnet and a conductor (including a coil and a core) generates an electromotive force e that is proportional to a magnetic field intensity B, a length of conductor L, and a relative velocity v between the magnetic field and the conductor, as defined by the following equation (Fleming's right hand rule).e=B·l·v  (1)
In general, the generator is implemented as a cylindrical two-pole single-phase generator or three-phase alternating-current generator, which includes a magnet and a conductor with one being a rotor and the other being a stator, in order to obtain the maximum electromotive force in a minimum space.
The basic structure of the three-phase alternating-current generator includes one two-pole magnet and three conductors (in case the magnet constitutes the rotor and the conductors constitute a stator) or three two-pole magnets and one conductor (in case the magnets constitute a rotor and the conductor constitutes a stator). Through the structure constructed in this manner, it is possible to enhance the efficiency of the generator by structurally appropriately arranging a plurality of magnets and a plurality of conductors in the structure, thereby increasing the electromotive force of the three-phase generator.
The electric apparatus is a generator and a motor at the same time. The reversibility between the generator and the motor can be explained via Fleming's right hand rule and left hand rule. The electric apparatus comes to be a generator and generates an electric current when the rotor is rotated by an external force, whereas it comes to be a motor which generates a force and rotates the rotor when an electric current is flowed in the conductor. That is, it can be said that the generator and the motor are quantitatively the same, and such a quantitative identity is related to energy conservation law.
For example, U.S. Pat. No. 7,791,241 describes a generator including a rotor having 4n magnets and a stator including 3n cores.